We try to keep our travel days below 250 miles, and stay at least 3 days. If you have a general direction, you might want to check this website. It gives you towns that are nearby that have RV parks, their customer ratings, and their amenities.
The site is sorted by state and then town.
http://www.campgroundreviews.com/
Don't forget to look at National and state parks, Army Corp of Engineering, boondocking sites, and overnights like Walmart or county fairgrounds. You can also sometimes stay overnight in a church parking lot.
We tried the big books and found they were way too cumbersome, usually the information was out of date, biased, and took too long to find and understand the information...they were poorly laid out and very confusing....got tired of flipping pages.